This invention relates to a pressure gauge, and more particularly to one which has a movable interior scale.
The improvement of this invention is directed to a conventional pressure gauge shown in FIG. 1 which is typically used to measure the air pressure in a tire. The conventional pressure gauge includes an adapter A for coupling with a tire's air valve, a tubular body B, and a movable scale C inserted partially into the tubular body B. The reading of the scale C is difficult. In addition, when impurities enter the interior of the tubular body B, the precision of the pressure gauge may be reduced.